Porous granular fibrous filter media are often used in solid-liquid separators and biotreatment apparatuses.
As an example of such filter media, PTL 1 proposes a filter medium in which a core yarn and a binder yarn, at least one of which is weldable, are twisted together with filament yarns placed between the core yarn and the binder yarn.
As another example, PTL 2 proposes a filter medium in which a core yarn and a binder yarn each blended with a bonding yarn are twisted together with filament yarns placed between the core yarn and the binder yarn. The filter media described above have the advantages of being lightweight, easy to handle, and easy to clean.